Quadruplex telegraphy.



No. 684,4!5. Patented Oct. l5, [90L- C. E. DIEHL.

OUADBUPLEX TELEGRAPHY.

(Applieatinp filed Feb. 25, 1901.) (No Model.)

WITNESSES: IN NTOR:

UNITED STATES PATENT OFFICE.

CLARK E. DIEHL, OF HARRISBURG, PENNSYLVANIA, ASSIGNOR TO POSTAL TELEGRAPH-CABLE COMPANY, OF NEW YORK, N. Y.

QUADRUPLEX TELEGRAPHY.

SPECIFICATION formingpart of Letters Patent No. 684,415, dated October 15, 1901.

Application filed February 25, 1901. Serial No. 48,652. (No model.)

To aZZ whom it may concern: 28 with the key it and local dynamo 6, 7 be- Be it known that I, CLARK E. DIEHL, a citiing an artificial resistance common to all the zen of the United States, residing in Harrislocal circuits. 55

burg, in the county of Dauphin and State of p is the current-changing transmitter by Pennsylvania, have made certain new and which a second set of signals are thrown upon usefulImprovernentsin QuadruplexTelegrathe line, whichare entirely independent of phy, of which the following is a specification. the first-named set. The magnet of p is in Hyinvention relates to a telegraph in which the local circuit 29 with the key j. The main- 6o one set of signals is transmitted by variations line fragment 10 is connected to the arma- To in strength of current and another set of sigture-lever 27. The back contact 26 is connals is transmitted by variations in the polarnected to armature-lever 24. through conducity of such current. At the receiving-station tor 25. The front contact 23 is connected to there is a neutral relay for the first-named armature-lever 21 through the conductor 22. 65 signals and a polarized relay for the second The dynamo 2 is connected to the front conset of signals, each relay operating a sounder tact 14 of t by conductor 13. The dynamo 3 through an appropriate local circuit. is connected to the back contact 16 of i by The object of my invention is to avoid the conductor 15. The dynamo 4 is connected to false signals liable to occur when a current the front contact 18 of magnet a by conduc- 7o impulse effective to operate the neutral relay tor 17. The dynamo 5 is connected. to the 20 has its polarity reversed by the operationof back contact 20 of "a by conductor 19. One the transmitter to vary the polarity, of such pole of the dynamos 2 and 4. is connected to impulse. ground. The opposite pole of dynamos 3 and I include between the contact-points of the 5 is connected to ground. 75 neutral relay and the sounder controlled by it The key It in the local circuit 28, including 2 5 an electromagnetic circuit-breaker. A local magnets and u, when closed carries armacircuit through the coils of this electromagtures 21 and2 l to their front contacts 14 and net is permanently closed, and the relay on 18, respectively. Dynamos 2 and 4, of the its back contact closes a shunt-circuit around same polarity, but difierent electromotive So the coils of the magnet. This renders the acforces, are thus connected to the contacts 23 0 tion of the magnet sluggish. I also prefer to and 26 of transmitterp. When keyk is open, employ for the described break-pointsaspring dynamos 3 and 5, of the same polarity, but normally engaging a fixed contact. The difierent electromotive forces, are connected spring is lifted from this contact by the arto contacts 23 and 26 of transmitterp. It is 85 mature-lever of the electromagnet, and I am to be noticed that when 70 is closed d ynamos thus enabled to increase the time interval reof the same polarity and different elcctroquired for a signal at the relay-contacts to motive forces are connected to points 23 and become eifective on the sounder. This time 26, respectively, and when key kis open the interval may thus be made sufficient to e1irnisame is true; but in the latter case thepolar- 9o nate false signals. ity of the dynamos connected to 23 and 26 is 40 The accompanying drawing illustrates my the reverse of what it was when 70 was invention. closed. For instance, when' k is open 23 and 1 is a main telegraph-line connecting two 26 will be connected to dynamos yielding plus separated stations. Signals are transmitted three hundred volts and one hundred volts, 5 by dynamos or generators 2 3, of opposite porespectively, and when key 7c is closed points larity and one electromotive force, and dyna- 23 and 26 will be connected to dynamos yieldmos a 5, of opposite polarity and a lower elecing minus three hundred volts and one huntromotive force than that due to 2 and 3. dred volts, respectively. Key j is therefore tand uare electromagnetic circuit-changers always free to throw upon the line current 10c and together constitute a transmitter for of one polarity or the other, depending upon 5o throwing upon the line a set of signals due to the condition of key it. The strength of curvariations in polarity of current. The elecrent so thrown upon the line by key j depends tromagnets are included in the local circuit upon whether it, 7', is closed or open. When j open, lever 27, connected to line, will rest on stop 26, and a current of one hundred minus, let us assume, will go to line. When j is closed, lever 27 rests 011 stop 23, and a current of three hundred minus under the same assumption will go to line, the key 70 being closed. If key 70 be in its opposite position from that assumed, the change of key j will result in passing from a current of one hundred plus to a current of three hundred plus. If, however, key j is directing a current of three hundred plus to line and key it is operated to reverse the polarity of the current while j maintains its position, there will be a short interval of no current, because it is not practicable to preserve the continuity of contact between the line and the dynamos during the reversal, and the'interval of no 7 current is somewhat more extended than is the case Where chemical generators are used, because the low internal resistance of the dynamos creates a practically short circuit, including two dynamos of opposite polarity, and this results in burning or melting the contact-points. To obviate this difficulty, there is necessary an interval of no current, and it is this extended interval of no current, due to the use of dynamo-machines for signaling, that the present improvement overcomes. The interval of no current is measured by the time it takes levers 21 and 24 to pass over from contacts 14 and 18 to contacts 16 and 20.

The receiviug-relays consist of ,the polarrelay d, differentially Wound, and operating sounder 32 through the local circuit 31, con-- nected to the local dynamo 6. The neutral relay 1) is composed of a compound lever a, pivoted at 53. There are two main-line coils 50 and 5l,differentially wound, upon opposite sides of the lever a and affecting it in the same direction. The third coil 52 is in a local circuit 30 with the primary coil h of an inductorium, the secondary coil of which is differentially wound and is included in the main and artificial line in a well-known manner. The neutral relay 12 operates the sounder 8, upon which the signals are received. Sounder sis in a local circuit 37 with the dynamo 6, the contact-point 39, and the springcontact 38. The magnet q, operating the lever 40, makes and breaks contact at 38 39. Magnet q is in a constantly-closed circuit 33, including the dynamo 6. 'lhereis ashunt formed upon the coils g by the conductor 34, extending from the local circuit 33 at one side of q to lhelever a of'relay b, and the conductor 36, connected to the local circuit 33 upon the opposite side of magnet q and extending to the back contact 35 of relay 1). The main-line fragment 10 connects the transmitting system with the main-line branch 11, which includes one differential coil of 50, 51, d, and 2', continuing to the distant station as main line 1. The artificial line l2 includes the second dilferentialcoil of 50, 51, d, and 2', passing through the adjustable rheostat S,

around which is connected the condenser c" and the rheostat 9 in a well-known manner.

The operation is as follows: Let us assume two sets of signals to be transmitted from the distant station and that an impulse of current, effective to close lever a of the neutral relay b upon its front contact, is present in the line and that during this interval the current is reversed in the process of transmitting a second and independent set of signals. Lever a will temporarily, leave its front contact; but this is not effective in the circuit of sounder 8. To affect sounder s, levera must rest upon its back contact 35' and shunt the current from the coils of q long enough to demagnet and due to the sluggish action of the magnet q whenfthe shunt 34 36 is formed is sufficient to bridge the time of reversal due to the operation of the polechanging transmitter 25 and u.

hat I claim, and desire to secure'by Letters Patent, is-

1. In a quadruplex telegraph the combination of four grounded dynamos arranged in two pairs of respectively opposite polarity and different electromotive forces, two transmitters and suitable circuit connections therefor, one of which when operated reverses the polarity of the dynamo connected to line,- the other of which changes from a dynamo of one electroinoiive force to the other, a relay responsive to changes of polarity for one set of signals, a relay responsive to changes in cur- .rent strength for a second set of signals, a

sounder and local circuit for the last-named relay, break-points in said sounder-circuit, an intermediate electromagnet controlling said break-points, a permanently-closed local circuit containing the coils of'said intermediate magnet,-a shunt or short circuit around the coils of said magnet and break-points con trolled by said relay included in said-shuntcircuit.

of opposite polarity and different electromo: tive force, two mechanically-independent transmitters electrically connected together,

and to line, one of which changes the polarity 40hasstruckuponspring38. Thetimegained 7' led and the other the electromotive force of the current sent to linc,a polarized and a neutral relayresponsive to said transmitters, respectively, a local-relay magnet in a permanentlyclosed local circuit, a shunt-circuituaround' said magnet-coils including the main-linerelay contact-points, and an electromagnetic sounder in a local circuit including a spring contact-pointcontrolled by said local relay.

CLARK E, DIEHLQ Witnesses: a

ANDREW S. IVIOCREATH, J r., CHARLES C. STROH.

r I V 2. In a quadruplex telegraph thecombina- V i tion of four dynamos arranged in two pairs 

